private AssignStat AssignStat()
{
string first = "id";
this.SkipErrors(first);
var lookaheadToken = this.TokenStream.Peek();
string lookahead = lookaheadToken.AToCCFormat();
if (first.HasToken(lookahead))
{
this.ApplyDerivation("assignStat -> variable '=' expr");
var assignStatement = new AssignStat(lookaheadToken.SourceLocation);
var variable = Variable();
Match("=");
var expr = Expr();
assignStatement.Variable = variable;
assignStatement.ExpressionValue = expr;
return(assignStatement);
}
return(null);
}
public override void Visit(AssignStat assignStat)
{
if (assignStat.ExpressionValue is Node expression)
{
if (assignStat.Variable.SemanticalType != expression.SemanticalType)
{
ErrorManager.Add($"Could not convert {expression.SemanticalType} to a {assignStat.Variable.SemanticalType}.", assignStat.Location);
}
assignStat.SemanticalType = expression.SemanticalType;
}
else
{
ErrorManager.Add($"Could not establish an expression value.", assignStat.Location);
}
}
} // NT_Stat
private static void NT_IncDecAssignOrCallStat(out Stat s)
{
int spix = 0;
Symbol sy = null;
Expr lhs = null, e = null;
SrcPos sp = null;
s = null;
for (;;)
{
switch (Syn.Interpret())
{
case 0:
return;
case 1:
Lex.GETidentAttr(out spix);
break;
case 2: // SEM
sy = SymTab.SymbolOf(spix, Symbol.Kind.varKind,
Symbol.Kind.parKind,
Symbol.Kind.funcKind);
break;
case 3: // SEM
s = new IncStat(sp, new VarOperand(sy));
break;
case 4: // SEM
s = new DecStat(sp, new VarOperand(sy));
break;
case 5: // SEM
lhs = new VarOperand(sy);
break;
case 6: // SEM
sp = new SrcPos();
break;
case 7:
NT_Expr(out e);
break;
case 8: // SEM
lhs = new ArrIdxOperator(sp, new VarOperand(sy), e);
break;
case 9: // SEM
sp = new SrcPos();
break;
case 10:
NT_Expr(out e);
break;
case 11: // SEM
s = new AssignStat(sp, lhs, e);
break;
case 12: // SEM
sp = new SrcPos();
break;
case 13:
NT_ActParList(out e);
break;
case 14: // SEM
s = new CallStat(sp, sy, e);
break;
} // switch
} // for
} // NT_IncDecAssignOrCallStat
} // NT_ConstDecl
private static void NT_Init(out Stat s,
ref Symbol sy)
{
int fact = 1, number = 0;
s = null;
for (;;)
{
switch (Syn.Interpret())
{
case 0:
return;
case 1: // SEM
if (sy.type != Type.boolType)
{
SemErr("invalid type");
}
sy.val = 0;
break;
case 2: // SEM
if (sy.type != Type.boolType)
{
SemErr("invalid type");
}
sy.val = 1;
break;
case 3: // SEM
fact = -1;
break;
case 4:
Lex.GETnumberAttr(out number);
break;
case 5: // SEM
if (sy.type.IsPtrType())
{
if (number != 0)
{
SemErr("invalid value");
}
}
else if (sy.type.kind != Type.Kind.intKind)
{
SemErr("invalid type");
}
sy.val = fact * number;
break;
case 6: // SEM
if (sy.kind == Symbol.Kind.varKind && loopLevel > 0)
{
s = new AssignStat(new SrcPos(),
new VarOperand(sy),
new LitOperand(sy.type, sy.val));
}
break;
} // switch
} // for
} // NT_Init
private static void CgAssignStat(FuncInfo fi, AssignStat node)
{
var exps = RemoveTailNil(node.ExpList);
var nExps = exps.Count;
var nVars = node.VarList.Count;
var tRegs = new int[nVars];
var kRegs = new int[nVars];
var vRegs = new int[nVars];
var oldRegs = fi.UsedRegs;
for (var i = 0; i < node.VarList.Count; i++)
{
var exp = node.VarList[i];
if (exp is TableAccessExp tableAccessExp)
{
tRegs[i] = fi.AllocReg();
CgExp(fi, tableAccessExp.PrefixExp, tRegs[i], 1);
kRegs[i] = fi.AllocReg();
CgExp(fi, tableAccessExp.KeyExp, kRegs[i], 1);
}
else if (exp is NameExp nameExp)
{
var name = nameExp.Name;
if (fi.SlotOfLocVar(name) < 0 && fi.IndexOfUpval(name) < 0)
{
kRegs[i] = -1;
fi.IndexOfConstant(name, out var constIdx);
if (constIdx > 0xff)
{
kRegs[i] = fi.AllocReg();
}
}
}
}
for (var i = 0; i < nVars; i++)
{
vRegs[i] = fi.UsedRegs + i;
}
if (nExps >= nVars)
{
for (var i = 0; i < exps.Count; i++)
{
var exp = exps[i];
var a = fi.AllocReg();
if (i >= nVars && i == nExps - 1 && IsVarargOrFuncCall(exp))
{
CgExp(fi, exp, a, 0);
}
else
{
CgExp(fi, exp, a, 1);
}
}
}
else
{
var multRet = false;
for (var i = 0; i < exps.Count; i++)
{
var exp = exps[i];
var a = fi.AllocReg();
if (i == nExps - 1 && IsVarargOrFuncCall(exp))
{
multRet = true;
var n = nVars - nExps + 1;
CgExp(fi, exp, a, n);
fi.AllocRegs(n - 1);
}
else
{
CgExp(fi, exp, a, 1);
}
}
if (!multRet)
{
var n = nVars - nExps;
var a = fi.AllocRegs(n);
fi.EmitLoadNil(a, n);
}
}
for (var i = 0; i < node.VarList.Count; i++)
{
var exp = node.VarList[i];
if (exp is NameExp nameExp)
{
var varName = nameExp.Name;
var a = fi.SlotOfLocVar(varName);
if (a >= 0)
{
fi.EmitMove(a, vRegs[i]);
}
else
{
var b = fi.IndexOfUpval(varName);
if (b >= 0)
{
fi.EmitSetUpval(vRegs[i], b);
}
else
{
a = fi.SlotOfLocVar("_ENV");
if (a >= 0)
{
if (kRegs[i] < 0)
{
fi.IndexOfConstant(varName, out var constIdx);
b = 0x100 + constIdx;
fi.EmitSetTable(a, b, vRegs[i]);
}
else
{
fi.EmitSetTable(a, kRegs[i], vRegs[i]);
}
}
else
{
a = fi.IndexOfUpval("_ENV");
if (kRegs[i] < 0)
{
fi.IndexOfConstant(varName, out var idx);
b = 0x100 + idx;
fi.EmitSetTabUp(a, b, vRegs[i]);
}
else
{
fi.EmitSetTable(a, kRegs[i], vRegs[i]);
}
}
}
}
}
else
{
fi.EmitSetTable(tRegs[i], kRegs[i], vRegs[i]);
}
}
fi.UsedRegs = oldRegs;
}
} // DumpSymTab
// === generate source text from symbol table and AST ===
public static void WriteStat(Stat stat)
{
switch (stat.kind)
{
case Stat.Kind.emptyStatKind:
genMcpp.WriteLine(Indent() + ";");
break;
case Stat.Kind.blockStatKind:
BlockStat b_s = (BlockStat)stat;
genMcpp.WriteLine(Indent() + "{");
IncIndent();
WriteStatList(b_s.statList);
DecIndent();
genMcpp.WriteLine(Indent() + "}");
break;
case Stat.Kind.incStatKind:
IncStat i_s = (IncStat)stat;
genMcpp.WriteLine(Indent() + i_s.vo.sy + "++;");
break;
case Stat.Kind.decStatKind:
DecStat d_s = (DecStat)stat;
genMcpp.WriteLine(Indent() + d_s.vo.sy + "--;");
break;
case Stat.Kind.assignStatKind:
AssignStat a_s = (AssignStat)stat;
genMcpp.WriteLine(Indent() + a_s.lhs + " = " + a_s.rhs + ";");
break;
case Stat.Kind.callStatKind:
CallStat c_s = (CallStat)stat;
genMcpp.WriteLine(Indent() + c_s.func + "(" + c_s.apl + ");");
break;
case Stat.Kind.ifStatKind:
IfStat if_s = (IfStat)stat;
genMcpp.WriteLine(Indent() + "if (" + if_s.cond + ")");
IncIndent();
WriteStatList(if_s.thenStat);
DecIndent();
if (if_s.elseStat != null)
{
genMcpp.WriteLine(Indent() + "else ");
IncIndent();
WriteStatList(if_s.elseStat);
DecIndent();
} // if
break;
case Stat.Kind.whileStatKind:
WhileStat w_s = (WhileStat)stat;
genMcpp.WriteLine(Indent() + "while (" + w_s.cond + ")");
IncIndent();
WriteStatList(w_s.body);
DecIndent();
break;
case Stat.Kind.breakStatKind:
genMcpp.WriteLine(Indent() + "break;");
break;
case Stat.Kind.inputStatKind:
InputStat in_s = (InputStat)stat;
genMcpp.WriteLine(Indent() + "cin >> " + in_s.vo.sy + ";");
break;
case Stat.Kind.outputStatKind:
OutputStat out_s = (OutputStat)stat;
genMcpp.Write(Indent() + "cout");
foreach (Object o in out_s.values)
{
genMcpp.Write(" << ");
if (o is Expr)
{
genMcpp.Write(o);
}
else if (o is String)
{
String s = o as String;
if (s == "\n")
{
genMcpp.Write("endl");
}
else
{
genMcpp.Write('"' + s + '"');
}
}
else
{
throw new Exception("invalid value");
}
} // foreach
genMcpp.WriteLine(";");
break;
case Stat.Kind.deleteStatKind:
DeleteStat del_s = (DeleteStat)stat;
genMcpp.WriteLine(Indent() + "delete[] " +
NameList.NameOf(del_s.vo.sy.spix) + ";");
break;
case Stat.Kind.returnStatKind:
ReturnStat r_s = (ReturnStat)stat;
genMcpp.Write(Indent() + "return");
if (r_s.e != null)
{
genMcpp.Write(" " + r_s.e);
}
genMcpp.WriteLine(";");
break;
default:
throw new Exception("invalid statement kind");
} // switch
} // WriteStatList
public virtual void Visit(AssignStat assignStat)
{
}
public override void Visit(AssignStat assignStat)
{
this.LoadAndStore(assignStat.ExpressionValue, assignStat.Variable, assignStat.ExpressionValue.NodeMemorySize, $"{assignStat}");
}
